J. Chem. Ens. Data 1983, 28, 410-412
410
Excess Thermodynamic Functions for Ternary Systems. 9. Total-Pressure Data and GE for Water/Ethylene Glycol/Ethanol at 50 OC Carlos Gonzalez and Hendrick C. Van Ness' Chemical and Environmental Engineering Department, Rensselaer Polytechnic Institute, Troy, New York 12 18 1
Isothermal P-x data for the ternary system water/ethylene glycd/ethanol at 50 O C are reported, together wlth data for the constituent Mnarles. Data reduction by Barker's method provider a correlatlon for GE. Reported here are vapor/liquid equilibrium (VLE) measurements for the water (l)/ethylene glycol (2)lethanol (3) system at 50 O C . Experimental values of total vapor pressure are given over the full composition range of the three constituent binaries and for five runs with ternary mixtures formed by addition of a pure species to mixtures of the other two. The apparatus is that of Gibbs and Van Ness ( 1 ) as modified by DiElsi et al. (2).
Table I. P-x Data for Water (l)/Ethylene Glycol ( 2 ) at 50 " C X1
0.0185 0.0479 0.0991 0.1500 0.1990 0.3006 0.3506 0.4009 0.4506 0.5006 0.5020
x2
P, kPa
0.9815 0.9521 0.9009 0.8500 0.8010 0.6994 0.6494 0.5991 0.5494 0.4994 0.4980
0.316 0.634 1.185 1.753 2.315 3.524 4.157 4.758 5.411 6.023 5.978
x,
0.5494 0.5994 0.6494 0.6995 0.7498 0.8000 0.8501 0.8999 0.9502 0.9803
P, kPa
x,
0.4506 0.4006 0.3506 0.3005 0.2502 0.2000 0.1499 0.1001 0.0498 0.0197
6.589 7.224 7.858 8.494 9.156 9.798 10.440 11.094 11.745 12.082
Table 11. P-3c Data for Water (l)/Ethanol ( 3 ) at 50 "C X1
0.0499 0.1004 0.1500 0.2002 0.2508 0.3003 0.3503 0.4010 0.4507 0.5004
x3
0.9501 0.8996 0.8500 0.7998 0.7492 0.6997 0.6497 0.5990 0.5493 0.4996
P,kPa 29.523 29.516 29.447 29.314 29.120 28.878 28.589 28.241 27.909 27.540
Xl
0.5006 0.5508 0.6007 0.6513 0.7004 0.7507 0.8006 0.8508 0.8720 0.9488
P, kPa
x3
0.4994 0.4492 0.3993 0.3487 0.2996 0.2493 0.1994 0.1492 0.1280 0.0512
27.521 27.113 26.665 26.182 25.680 25.010 24.185 22.993 22.274 17.821
Table 111. P-x Data for Ethylene Glycol (2)/ Ethanol ( 3 ) at 50 "C ~
x,
0.0203 0.0504 0.1093 0.1492 0.1982 0.2474 0.2974 0.3470 0.3968 0.4465 0.4962
x3
0.9797 0.9496 0.8907 0.8508 0.8018 0.7526 0.7026 0.6530 0.6032 0.5535 0.5038
P,kPa 28.900 28.090 26.567 25.625 24.502 23.418 22.337 21.278 20.210 19.128 18.027
2 2
0.5004 0.5495 0.5994 0.6494 0.7002 0.7501 0.8003 0.8464 0.8995 0.9420 0.9790
x3
0.4996 0.4505 0.4006 0.3506 0.2998 0.2499 0.1997 0.1536 0.1005 0.0580 0.0210
~~~
P,kPa 17.861 16.707 15.454 14.115 12.665 11.137 9.412 7.613 5.308 3.277 1.333
0021-956818311728-0410$01.50/0
Table IV. P-x Data for Water (l)/Ethylene Glycol (2)/Ethanol(3)at 50 "C Xl
0.4926 0.4744 0.4498 0.4244 0.3994 0.3745 0.3493 0.3239 0.2991 0.2742 0.2492 0.0304 0.0638 0.1251 0.1835 0.2405 0.2969 0.3527 0.4068 0.4593 0.5106 0.5605 0.0499 0.1002 0.1504 0.2005 0.2507 0.3003 0.3501 0.4003 0.4502 0.4990 0.6627 0.6517 0.6327 0.6124 0.5913 0.5691 0.5459 0.5212 0.4950 0.4547 0.4378 0.3250 0.3173 0.3042 0.2909 0.2773 0.2633 0.2488 0.2341 0.2188 0.2033 0.1873
X,
0.0204 0.0510 0.1006 0.1513 0.2014 0.2512 0.3015 0.3523 0.4019 0.4517 0.5016 0.6487 0.6264 0.5853 0.5462 0.5081 0.4704 0.4331 0.3968 0.3618 0.3274 0.2941 0.3137 0.2971 0.2805 0.2640 0.2474 0.2310 0.2146 0.1980 0.1815 0.1654 0.3266 0.3211 0.3118 0.3018 0.2914 0.2804 0.2690 0.2568 0.2439 0.2241 0.2157 0.6595 0.6438 0.6172 0.5904 0.5627 0.5344 0.5050 0.4750 0.4440 0.4125 0.3800
3c3
0.4870 0.4746 0.4496 0.4243 0.3992 0.3744 0.3492 0.3238 0.2990 0.2741 0.2492 0.3209 0.3099 0.2896 0.2703 0.2514 0.2327 0.2142 0.1963 0.1790 0.1620 0.1455 0.6364 0.6027 0.5691 0.5355 0.5019 0.4687 0.4353 0.4017 0.3683 0.3356 0.0107 0.0272 0.0555 0.0858 0.1174 0.1504 0.1851 0.2220 0.2611 0.3212 0.3464 0.0155 0.0389 0.0786 0.1187 0.1600 0.2023 0.2462 0.2909 0.3372 0.3842 0.4328
P, kPa 26.813 26.145 25.048 23.903 22.707 21.574 20.358 19.132 17.903 16.637 15.333 13.768 14.012 14.467 14.895 15.290 15.665 16.024 16.340 16.617 16.851 17.015 21.870 22.155 22.362 22.568 22.739 22.876 23.049 23.076 23.097 23.060 9.144 10.572 12.713 14.515 16.090 17.428 18.591 19.621 20.551 21.748 22.188 4.879 6.407 8.692 10.645 12.360 13.890 15.264 16.507 17.655 18.638 19.773
Reagent-quality ethanol with an indicated purity of 99.9 mol % was supplied by U.S. Industrial Chemicals. The ethylene glycol was a chromatoquality reagent with a purity >99.5 mol % from Matheson Coleman and Bell. The water was doubly deionzed. All reagents were thoroughly degassed.
0 1983 American Chemical Society
Journal of Chemical and Engineering Data, Vol. 28, No. 4, 7983 411 --l
Table V. Summary of Results for Binary Systems at 50 "Ca
Pisat,kPa P.sat,kPa cm3/mol 5 ,cm3/mol Bii, cm3/mol Bjj, cm3/mol Bij, cm3/mol Aij Aji
+it,
water (1)/ ethylene glycol (2)
ethylene water (1)/ glycol (2)/ ethanol (3) ethanol (3)
12.345 0.116 18 57 -1137 -1970 -1246 -0.14939 -0.14939
12.345 29.476 18 60 -1137 - 1400 -1168 0.93116 1.59918 0.32660 -0.32480 0.54830 -1.87888 0.012 0.024
ij
hji qij Qji
rms SP,kPa max ISPI, kPa a
- - 7
0.025 0.048
0.116 29.476 51 60 -1970 - 1400 -1729 0.83640 0.70498 0.20563 0.05615 0.019 0.048
Pairs of species are listed in the order i, j . n
L
Figure 2. Plctorial view of the GE-x surface for the water (l)/ethylene glycol (2)hthanol(3) system at 50 OC.
Figure 1. Lines of constant GE(J/mol) for the water (l)/ethyleneglycol (2)/ethanol(3) system at 50 OC.
Results and Correlations Tables 1-111 give experimental values of total pressure for the three constituent binary systems, and Table I V presents the data for ternary mixtures. Data reduction is by Barker's method, as described earlier (3, 4). For the binary systems, the Margules equation with up to six parameters provides suitable expression of GE. g,/ = G ~ / R T= [A,+,
+ A e j - C X j , + Ae,)x+j + ( 7 ,+~~ ~ j ( x + j Y I x + (1) j
For the water (l)/ethanol (3) system, correlation requires all six parameters; for ethylene glycol (2)/ethanol (3), 723 = 732 = 0; and for water (l)/ethylene glycol (2),712= 721= A,, = A,, = 0 and A , , = A 2 1 . Data for the ternary system are adequately correlated by the three-parameter Wohl equation: 9123
= g12 + g13 + 9 2 3
+ ( c O + clxl+ c 2 x P ) x 1 x 2 x 3
(2)
Correlations for the g, are given by eq 1; parameters Co,C l , and C, result from regression of just the ternary data. Second virial coefficients Bv required for estimation of vapor-phase nonidealities come from the correlation of Hayden and O'Connell (5).
Lines of constant P (kPa) for the water (l)/ethyleneglycol (2)/ethanol(3) system at 50 O C .
Figure 3.
Results of correlation for the binary systems, together with all ancillary information, are summarized in Table V. With parameters for the binary systems fixed at the values of Table V, the ternary-mixture data are correlated when the parameters of eq 2 have the following values: Co= 1.1616; C1 = 0.6820; C, = 0.5229. The root-mean-square (rms) value of 6P for the ternary data is 0.081 kPa; the maximum value of l6Pl is 0.235 kPa. Dlscusslon
No data comparable with ours for the water/ethylene glycol and ethylene glycol/ethanol binary systems or for the ternary system appear in the literature. The data of Pemberton and Mash (6) for water/ethanol at 50 OC are in almost perfect agreement with ours. The results of this study are shown in Figures 1-3. Figure 1 is a contour diagram showing lines of constant GEon a triangular mole fraction grid. Figure 2 is an oblique view of the
J. Chem. Eng. Data 1983, 28, 412-419
412
same surface, and Figure 3 is a contour diagram showing lines
Greek Letters
of constant P. The only azeotrope is for the water/ethanol binary system at x , = 0.0641 and P" = 29.537 kPa.
A,, A),, 6
parameters in eq 1
'" 77,
1
denotes the difference, calculated
- experimental
Reglsltry No. Ethylene glycol, 107-21-1; ethanol, 64-17-5.
parameters in eq 1 second virial coefficient parameters in eq 2
Llterature Ctted (1) Gibbs,
excess Gibbs function, liquid phase G~IRT total pressure vapor pressure of pure i universal gas constant absolute temperature molar volume of pure liquid i mole fraction, liquid phase
410.
R. E.; Van Ness, H. C. Ind. Eng. Chem. fundam. 1872,
71,
(2) DIElsl, D. P.;Patel, R. B.; Abbott, M. M.; Van Ness, H. C. J . Chem. Eng. Data 1878, 23, 242. (3) Abbott, M. M.; Van Ness, H. C. AIChE J . 1875, 21, 62. (4) Abbott, M. M.; Floess, J. K.; Walsh, G. E.; Van Ness, H. C. AIChE J . 1975, 21, 72. (5) Hayden, J. G.; O'Connell. J. P. Ind. Eng. Chem. Process Des. D e v . 1875, 1 4 , 209. (6) Pemberton, R. C.; Mash, C. J. J . Chem. T h e f m n . 1878, 70, 867. Received for review January 17, 1983. Accepted March 18, 1983.
Total-Pressure Vapor-Liquid Equilibrium Data for Binary Systems of Dichloromethane with Pentane, Acetone, Ethyl Acetate, Methanol, and Acetonitrile JagjR R. Khurma, 01 Muthu, Sarat Munlal, and Buford D. SmRh" Thermodynamics Research Laboratory, Washington University, St. Louis, Missouri 63 130 Table
Total-pressure vapor-llguld equlllbrlum (VLE) data are reported at approxlmately 298, 348, and 398 K for dlchloromethane wlth pentane, acetone, ethyl acetate, methanol, and acetonltrlle. The experlmental PTx data were reduced to y,, y,,and GE values by both the Mlxon-Gumowskl-Carpenter and the Barker methods and the results compared. SIX GE correlatlons were tested In the Barker data reductlon; the Hve-constant Redllch-Klster equation gave the best results. The Peng-RoMnson equatlon of state was used for all the data reductlon calculations.
I.
C h e m i c a l s Used
component
vendor
stated purity, %
ethyl acetate acetone methanol pentane acetonitrile dichloromethane
Burdick and Jackson Burdick and Jackson Fisher Scientific Burdick and Jackson Burdick and Jackson Burdick and Jackson
99.9 99.9+ 99.9 99.9 99.9+ 99.9
Table 11. ExperimentalP vs. x , Data for t h e Pentane (1 ) + D i c h l o r o m e t h a n e ( 2 ) S y s t e m
- - - - - -.
298.19 K
348.11 K
P, KPA
_________________
I ntroductlon
XI
EXPTL
SKUm
0.0 0.0331 0.0857 0.1510 0,2213 0.3012 0.4091 0.5011 0.5970 0.6945 0.1792 0.8185 0.8998 0,9491 1.0000
58.35 63.98 69.49 14.24 77.46 19.84 81.14 82.46 82.39 81.61 19.90 18.13 75.30 12 45 68.41
58.36 63.95 69.56 14.10 17.49 19.84 01.74 82.45 02.42 81.58 79.90 70.13 75.33 12.43 68.41
XI
- - - - - - .._-_-_--_--_______-_ - - - - - - - -.
This paper presents total-pressure vapor-liquid equilibrium (VLE) data for five binary systems for dlchloromethane with pentane, acetone, ethyl acetate, methanol, and acetonitrile. Data for each binary were measured at approximately 298, 348, and 398 K. The techniques and apparatus used to measure these data have been described previously along with the defining equation for the activity coefficient and the standard states used ( 7 ) .
Chemkals Used The sowces and the puritiis of the chemicals used are given in Table I. Activated molecular sieves,(either 3A or 4A) were put into the chemical containers as they were received. Just prior to being loaded in the VLE cells, each chemical was poured into a distillation flask and distilled through a Vigreux 0021-9568/83/1728-0412$01.50/0
0.0
0.0329 0.0054 0.I506 0.2209 0.3009 0.4095 0.5012 0.5975 0.6948 0.7196 0.8189 0.9002 0.9500 1 .oooo
308.1 325.8 343.2 358.5 369.6 311.9 384.2 385.4 382.6 317.3 368.8 363.4 349.5 338.0 323.9
308.1 325.8 343.3 358.3 369.1 378.1 384.1 385.2 382.9 317.2 368.8 363.5 349.4 338.1 323.9
- - - --X -I __ 0.0 0.0329 0.0853 0.1504 0,2207 0.3007 0.4097 0.5016 0.5987 0.6954 0.7801 0.8194 0.9005 0.9502 1.0000
1030.1 1061.4 1097.1 1131.6 1157.1 1116.0 1181.6 1184.2 1169.3 1147.1 1121.4 1105.9 1066.8 1037.5 1003.3
1030.2 1061.4 1091.4 1130.9 1151.3 1176.6 1187.1 1183.1 1169.8 1141.3 1120.9 1105.9 1067.1 1037.3 1003.3
column (25" 0.d. and 470 mm long). The first and last portions of each distillate were discarded. The retalned portions were caught in amber bottles and back-flushed wtth dry nitrogen for transfer to the celCloadlng operation. The stated purities of the chemicals were confirmed by gas-liquid chromatography. None of the compounds exhibited any degradation during the VLE measurements. The cell pressures were stable with re@ 1983 American Chemical Society
